A heavily armed member of the New York Police Department patrols Times Square Friday, June 29, 2007 in New York. (AP Photo/Mary Altaffer)A heavily armed member of the New York Police Department patrols Times Square Friday, June 29, 2007 in New York. (AP Photo/Mary Altaffer)

NEW YORK (CBSNewYork/AP) — Osama bin Laden, the glowering mastermind behind the Sept. 11, 2001, terror attacks that killed thousands of Americans, was slain in a firefight Sunday with U.S. forces in Pakistan, ending a manhunt that spanned a frustrating decade.

“Justice has been done,” President Barack Obama said in a dramatic late-night announcement at the White House.

“New Yorkers have waited nearly ten years for this news,” Mayor Michael Bloomberg said in a statement. “It is my hope that it will bring some closure and comfort to all those who lost loved ones on September 11, 2001.”

New York City resident Charles Wolf lost his wife, Katherine, on that fateful day. He said he was “extremely happy” that Osama bin Laden was killed.

“What a surprise – what a wonderful surprise,” Wolf said. “I am so glad that this man’s evil energy, that his evil being, is no longer on this earth.”

Sally Regenhard was one of the many mothers who lost a child in the September 11 terror attacks. Her son, Christian, was a 28-year-old probationary firefighter.

“I’m glad, and I feel very gratified that we finally have a modicum of justice, the families finally have a modicum of justice after 10 long years,” she said. “I feel it’s better late than never.”

New York lawmakers said the death of bin Laden was a huge step in the war on terror.

“The killing of Osama bin Laden does not lessen the suffering that New Yorkers and Americans experienced at his hands, but it is a critically important victory for our nation – and a tribute to the millions of men and women in our armed forces and elsewhere who have fought so hard for our nation,” Bloomberg said.

While many were jubilant that the mastermind of the worst terror attack in New York City history was dead, that excitement was tempered by the possibility for retaliation.

“We have to be on heightened alert now – other cities around the world, around the country, as well,” terrorism expert Robert Strang said. “We’re going to see more security in the United States, [and] right here in New York obviously. We’re going to see heightened police activity all over the country.”

President Obama struck a less than boastful tone in his brief announcement, although he said the death of bin Laden was “the most significant achievement to date in our nation’s effort to defeat al-Qaida.

“His death does not mark the end of our effort. There’s no doubt that al-Qaida will continue to pursue attacks against us. We must and we will remain vigilant,” he added. Moments after Obama spoke, the State Department put U.S. embassies on alert and warned of the heightened possibility for anti-American violence. In a worldwide travel alert, the department said there was an “enhanced potential for anti-American violence given recent counterterrorism activity in Pakistan.”

“This is huge for us, it’s a major victory, and hopefully the beginning of the end of terrorism as we know it,” Strang said.